Breeding for aluminum tolerance
Aluminum-tolerant genotypes have been identified.
Based on the patterns of aluminum accumulation in
plant tissue, three groups of aluminum-tolerant plants
may be identified: (i) those with an apparent exclusion
mechanism allowing lower accumulation of aluminum
in their roots than aluminum-sensitive plants (e.g.,
wheat, barley, soybean); (ii) those with less aluminum in
the shoot but more in the roots (e.g., wheat, barley,
potato); and (iii) those with high aluminum accumulation
in the shoot (e.g., pine trees). Research in wheat
suggests the possibility of more than one aluminumtolerance
gene and more than one aluminum-tolerance
mechanism. In one piece of research, two QTLs associated
with aluminum tolerance were identified in the F2
population of diploid alfalfa and confirmed in the backcross
population. Breeding aluminum tolerance helps to
expand crop productivity to acidic soils.